Commonly assigned prior art U.S. Pat. No. 5,357,303, issued Oct. 18, 1994, discloses a film cassette having a light lock which is pivoted closed to prevent ambient light from entering the cassette interior and is pivoted open to permit film movement out of and into the cassette interior. An implement or tool is designed to engage the light lock to pivot it open and closed.
Commonly assigned prior art U.S. Pat. No. 5,231,438, issued Jul. 27, 1993, discloses a camera intended for use with a film cassette having a light lock which is pivoted closed to prevent ambient light from entering the cassette interior and is pivoted open to permit film movement out of and into the cassette interior. The camera has a release button which when manually moved in a releasing direction actuates a latching device. The latching device normally secures a door closed over a chamber holding the film cassette. However, when the latching device is actuated, it operates to pivot the light lock closed and to release the door to uncover the chamber.